A new objective function for RPL routing protocol in IoT to increase network lifetime

Abstract

Internet of Things (IoT) uses Routing Protocol of Low Power and Lossy Networks (RPL) for routing task with an Objective Function (OF) which determines next hop of nodes with calculation of path cost. However, energy imbalance between nodes is considered as one of the main problems in RPL and causes increasing in energy consumption. In this paper, we design a new OF called Time OF (T-OF) to achieve balance between energy of the nodes to improve network lifetime. A new varying weighted combination of energy, Expected Transmission Count (ETX) and Number of Children and Siblings (NOCS) metrics is used. The proposed T-OF has been compared to Minimum Rank with Hysteresis Objective Function (MRHOF), Objective Function Zero (OF0), and Energy Objective Function (EN-OF). Experimental results show that the proposed OF improves network lifetime and energy balancing significantly owing to lower delay, 11.35 seconds and Packet Delivery Ratio (PDR) of 95%.